In a variety of clinical (valuable warm-blooded animal and human treatment) situations, the presence of too much extracellular fluid in body tissues (edema) can be a problem in itself, or a problem which interferes with the treatment of other associated abnormal or disease conditions of concern to the patient and/or physician. Examples of clinical circumstances that can be associated with edema include congestive heart failure, advanced hepatic cirrohosis, nephrotic syndrome, and chronic renal failure.
Many diuretic drug compounds are known for treatment of edema and lists of various commercially available diuretics can be found in various publications, e.g., the Physicians' Desk Reference (PDR), 34th Edition (1980), published by Charles E. Baker, Jr., Copyright 1980 by Litton Industries, Inc., Published by Medical Economics Company, a Litton division at Oradell, NJ 07649, under DIURETICS on pp. 216-217 thereof. However, at least some of these known listed diuretic agents cause excretion of substantial amounts of potassium ions necessitating that care is taken to avoid the urinary elimination of too much potassium which is needed to maintain normal ion balance in the body.
In other clinical situations, blood pressure may be abnormally elevated for reasons known or unknown. Diuretic drug compounds, either because of their ability to remove extracellular fluid itself or because of some other pharmacological property, also frequently lower abnormally elevated blood pressure.
Moreover, some compounds which initially show promise as diuretic drugs are often later dropped from consideration as diuretic drugs because of toxicity or other undesired properties of the compounds.
Persons in the art concerned with the search for safe diuretic and natriuretic drugs continue to look for drugs which will effectively remove water and sodium ion without also depleting the potassium ion levels of the body to below acceptable levels.